Under the state's speed trap law, a city can only receive up to 30 percent of total expenditures from fines and fees. An audit found that between 40 and 45 percent of Cash's expenditures could be covered by revenue from fines, forfeitures and costs.

But the prosecutor's letter says that figure includes fines and costs from Arkansas State Police citations and non-traffic offenses. In his letter, Deprow recommended that the city modify its accounting procedures to distinguish between traffic and non-traffic fines.